{"id":"mr-and-biology-guided-radiotherapy-roadmap","name":"MR-linacs and biology-guided radiotherapy: from a cobalt MRI machine to PET-guided beams","route":"/roadmaps/mr-and-biology-guided-radiotherapy-roadmap/","eras":[{"era":"2012-2016","title":"MRI with cobalt","description":"The ViewRay System (K111862, May 2012) paired a low-field MRI with three cobalt-60 heads so soft tissue could be seen during treatment. Cobalt limited beam sharpness and dose rate.","status":"historic","refs":[{"id":"mr-linac","kind":"technology","name":"MR-guided adaptive radiotherapy","route":"/technologies/mr-linac/","status":"established","tldr":"An MR-linac is a radiation machine with an MRI scanner built in, so images taken during setup let the plan be re-optimised in minutes to that day's anatomy. It allows tighter margins and higher doses in pancreatic and prostate cancer, but treatment is slow and costly, and whether daily adaptation improves cure rates rather than only toxicity is unproven."},{"id":"viewray","kind":"company","name":"ViewRay (MRIdian)","route":"/companies/viewray/","tldr":"ViewRay makes MRIdian, the MR-linac that pairs a low-field MRI with a linear accelerator so tumours in the pancreas, liver and prostate can be watched and the beam gated while it treats; the original company went bankrupt in 2023 and the business continues under new ownership."},{"id":"cobalt-60-teletherapy","kind":"technology","name":"Cobalt-60 teletherapy","route":"/technologies/cobalt-60-teletherapy/","status":"historic","tldr":"The machine that made curative radiotherapy widely available from the 1950s: a sealed cobalt-60 source in a rotating head. Linacs replaced it in rich countries, but cobalt units still treat many patients where power and servicing are unreliable."}],"trials":[],"papers":[]},{"era":"2017-2021","title":"MR-linacs","description":"The MRIdian Linac (K162393, February 2017) replaced cobalt with a linac; Elekta Unity (K182076, December 2018) put a 7 MV linac around a 1.5 tesla MRI. Daily online adaptation and gating on soft tissue became routine at the centres that bought them, and MIRAGE showed less toxicity with MR-guided prostate stereotactic treatment.","status":"historic","refs":[{"id":"mr-linac","kind":"technology","name":"MR-guided adaptive radiotherapy","route":"/technologies/mr-linac/","status":"established","tldr":"An MR-linac is a radiation machine with an MRI scanner built in, so images taken during setup let the plan be re-optimised in minutes to that day's anatomy. It allows tighter margins and higher doses in pancreatic and prostate cancer, but treatment is slow and costly, and whether daily adaptation improves cure rates rather than only toxicity is unproven."},{"id":"elekta","kind":"company","name":"Elekta","route":"/companies/elekta/","tldr":"Elekta is the Swedish radiotherapy company behind Unity, the leading MR-linac, and Gamma Knife."},{"id":"viewray","kind":"company","name":"ViewRay (MRIdian)","route":"/companies/viewray/","tldr":"ViewRay makes MRIdian, the MR-linac that pairs a low-field MRI with a linear accelerator so tumours in the pancreas, liver and prostate can be watched and the beam gated while it treats; the original company went bankrupt in 2023 and the business continues under new ownership."},{"id":"adaptive-radiotherapy","kind":"technology","name":"Adaptive radiotherapy (online replanning)","route":"/technologies/adaptive-radiotherapy/","status":"emerging","tldr":"Re-shaping the treatment plan to the anatomy of the day, using the images taken on the treatment couch, so the dose follows a shrinking tumour or a moving bladder."}],"trials":[],"papers":[]},{"era":"2023-2024","title":"Bankruptcy and a new owner","description":"ViewRay filed for Chapter 11 in July 2023. ViewRay Systems, established on 6 February 2024 after acquiring the assets, designs, makes and sells the MRIdian A3i, described as adding brain treatment and real-time 3D tissue tracking.","status":"current","refs":[{"id":"viewray","kind":"company","name":"ViewRay (MRIdian)","route":"/companies/viewray/","tldr":"ViewRay makes MRIdian, the MR-linac that pairs a low-field MRI with a linear accelerator so tumours in the pancreas, liver and prostate can be watched and the beam gated while it treats; the original company went bankrupt in 2023 and the business continues under new ownership."},{"id":"mr-linac","kind":"technology","name":"MR-guided adaptive radiotherapy","route":"/technologies/mr-linac/","status":"established","tldr":"An MR-linac is a radiation machine with an MRI scanner built in, so images taken during setup let the plan be re-optimised in minutes to that day's anatomy. It allows tighter margins and higher doses in pancreatic and prostate cancer, but treatment is slow and costly, and whether daily adaptation improves cure rates rather than only toxicity is unproven."}],"trials":[],"papers":[]},{"era":"2020-2026","title":"PET-guided beams","description":"RefleXion's X1 (K190978, 2020) added a PET subsystem to a ring linac; its SCINTIX biology-guided therapy was authorised by De Novo in February 2023 (DEN220014) for tumours in lung and bone, creating a new device type. The X2 (K252071, December 2025) uses four detector rows instead of one, widening the PET field from 5.3 to 21.5 cm.","status":"current","refs":[{"id":"biology-guided-radiotherapy","kind":"technology","name":"Biology-guided radiotherapy (RefleXion X1, SCINTIX)","route":"/technologies/biology-guided-radiotherapy/","status":"emerging","tldr":"A radiotherapy machine with PET detectors built in: the tumour's own radioactive tracer signal tells the beam where to fire, hundreds of times a second, so moving tumours and several metastases can be tracked and treated without external markers."},{"id":"reflexion","kind":"company","name":"RefleXion Medical","route":"/companies/reflexion/","tldr":"RefleXion Medical makes the first PET-guided radiotherapy system, which uses the tumour's own emissions to steer the beam."},{"id":"pet-ct","kind":"technology","name":"PET/CT","route":"/technologies/pet-ct/","status":"standard-of-care","tldr":"PET and CT in one machine, so hot spots on the PET are pinned to exact locations on the CT."}],"trials":[],"papers":[]},{"era":"Next","title":"Proving the benefit","description":"Throughput and cost limit both approaches, and whether daily adaptation improves cure rather than only toxicity is still being tested. A coordinated evidence programme for adaptive radiotherapy is proposed in OnCo.","status":"emerging","refs":[{"id":"idea-fund-adaptive-radiotherapy-evidence","kind":"idea","name":"Coverage-with-evidence registries for MR-guided and adaptive radiotherapy","route":"/ideas/idea-fund-adaptive-radiotherapy-evidence/","tldr":"Radiotherapy machines that adapt to the tumour each day cost far more than standard ones and their benefit is unproven. Payers would fund them only within registries and trials that measure whether they help."},{"id":"b-surgery-radiation-innovation","kind":"bottleneck","name":"Surgery and radiotherapy cure most, get least","route":"/bottlenecks/b-surgery-radiation-innovation/","tldr":"Surgery and radiotherapy cure more people than drugs do, but attract a fraction of the research investment."}],"trials":[],"papers":[]}],"watch":[]}